SALEM — Solar power facilities on high-value farmland in Oregon would have to clear a new hurdle under a bill being considered by state lawmakers.

Commercial developers would first have to demonstrate that alternative sites aren’t available under House Bill 3050, a requirement that currently applies to solar facilities larger than 12 acres.

Proponents of the bill, including the Oregon Farm Bureau and the 1,000 Friends of Oregon conservation group, say the new test would discourage conversion of the state’s most productive land.

An uptick in commercial solar power proposals in Oregon’s Willamette Valley has raised concerns that clusters of developments will change the agricultural character of affected areas, supporters say.

Such close groupings of solar facilities effectively undermine the current 12-acre exemption to the alternative analysis, according to proponents.

The growing popularity of long-term leases of farmland for commercial solar projects has prompted the Oregon Board of Agriculture to ask for a review of land use regulations for such sites.

Supporters of HB 3050 say that solar developments drive up rent prices for farmland even while long-term leases for solar panels may permanently take land out of agriculture.

The Oregon Farm Bureau was alerted to the problem by “mass mailings” from solar companies to farmers, said Mary Anne Nash, public policy counsel for the group.

Developers should first look for other options before seeking to lease high-value farmland, she said.

Wind turbine projects are already subject to the alternatives analysis requirement, so it should also apply to commercial solar facilities, said Meriel Darzen of 1,000 Friends of Oregon.

Critics of the bill countered that the new requirement is overly broad and ignores existing rules that protect farmland.

Marty Dozler, a farmer near Aumsville, Ore., said some of his property is considered high-value farmland even though the soils aren’t of the highest quality.

It’s tough to break even financially on this land, so solar development provides a new revenue source that makes the farm viable for the next generation, he said.

“We believe every farmer should be allowed to place solar facilities if they choose, regardless of where they live in the state,” Dozler said.

Dozler said he’s installed solar panels in the corners of fields and other areas that don’t interfere with farming practices.

“It’s a steady income with very little impact to our land,” he said.

Large power utilities are required by Oregon law to buy 8 percent of their electricity from small-scale renewable producers within 10 years, which HB 3050 will impede, said Damien Hall, attorney for Cypress Creek Renewables, a solar firm.

Clusters of solar projects greater than 48 acres in a one mile radius must already prove they don’t disrupt land use patterns, and current proposals would only build facilities on a tiny fraction of Oregon’s high-value farmland, he said.

“The impacts identified by supporters of this bill are hypothetical at this point,” Hall said.